Three-dimensional model data-providing program, three-dimensional model data-providing server, and three-dimensional model data transfer method

摘要

A three-dimensional model data-providing program which is capable of transferring image data by an appropriate one of data transfer methods, suited to the situation. When an application program delivers an instruction for drawing an image of the model, processing times are calculated which a command method and a differential image method will take to draw the image on the client, to select one which will take a shorter time. When the command method is determined to take a shorter time, data defining the model based on the instruction and data defining a display method for displaying the model are transmitted to the client. When the differential image method is determined to take a shorter time, a two-dimensional projected image is generated from the model based on the instruction and a differential image between the generated projected image and an immediately preceding projected image are transmitted to the client.